Age dependent alterations of host immune response in the ethanol-fed rat

The interaction between ethanol and aging with respect to cellular immune response is unclear. For our studies, Sprague-Dawley rats were pair fed using a synthetic liquid control diet (LCD) or a diet in which ethanol was substituted for carbohydrate (LED). The special diets were started when the rats' age varied from 1-18 months and were continued for one, two, or three months. In a second set of experiments, rats were treated continuously with these diets for 24 months. At each study period blood was drawn for serum and the spleen cells removed. Immune response was assessed by the lymphocyte transformation test using combinations of cells and serum from each of the rat groups. When LCD or LED were started in aged rats (18 months), after three months, there was a significant decrease in the Concanavalin A induced lymphocyte transformation test using the serum from LCD rats compared to serum from LED rats with either cells from LCD (1,273 +/- 831 (DPM +/- SD) vs 302 +/- 139; p less than 0.04) or cells from LED animals (984 +/- 338 vs 420 +/- 196; p less than 0.02). When the diet started at younger age or for less than three months these effects were not seen. In the continuously LCD or LED fed rats, the blastogenic response peaked at three months of treatment (four months of age) and decreased at six months and remained constant over the remainder of the 24 month period. There was no difference in lymphocyte DNA synthesis comparing any of the serum or cell groups with respect to diet.(ABSTRACT TRUNCATED AT 250 WORDS)